U.S. patent application number 16/268632 was filed with the patent office on 2020-08-06 for reed switch assembly having a customizable length of activation.
This patent application is currently assigned to Honeywell International Inc.. The applicant listed for this patent is Honeywell International Inc.. Invention is credited to Jeffrey ALEXANDER.
Application Number | 20200251296 16/268632 |
Document ID | / |
Family ID | 1000003885834 |
Filed Date | 2020-08-06 |
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United States Patent
Application |
20200251296 |
Kind Code |
A1 |
ALEXANDER; Jeffrey |
August 6, 2020 |
REED SWITCH ASSEMBLY HAVING A CUSTOMIZABLE LENGTH OF ACTIVATION
Abstract
A reed switch assembly having a customizable length of
activation is disclosed. One embodiment of the reed switch assembly
may comprise a reed switch comprising a first reed contact, a
second reed contact, a reed switch body enclosing the first reed
contact and the second reed contact, and a bias magnet. The bias
magnet may be positioned a certain distance away from the reed
switch body to close the reed switch by a magnetic field. The reed
switch assembly may further comprise a diversion blade that is
configured to move in and out of a space between the reed switch
body and the bias magnet. The diversion blade positioned in the
space may open the reed switch by diverting the magnetic field
applied by the bias magnet.
Inventors: |
ALEXANDER; Jeffrey;
(Atlanta, GA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Honeywell International Inc. |
Morris Plains |
NJ |
US |
|
|
Assignee: |
Honeywell International
Inc.
|
Family ID: |
1000003885834 |
Appl. No.: |
16/268632 |
Filed: |
February 6, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01H 50/44 20130101;
H01H 50/54 20130101; H01H 51/282 20130101; H01H 50/023 20130101;
H01H 50/18 20130101 |
International
Class: |
H01H 51/28 20060101
H01H051/28; H01H 50/18 20060101 H01H050/18; H01H 50/44 20060101
H01H050/44; H01H 50/54 20060101 H01H050/54 |
Claims
1. A reed switch assembly comprising: a reed switch comprising: a
first reed contact; a second reed contact; a reed switch body
defining a substantially straight channel and enclosing the first
reed switch contact and the second reed switch contact; and a bias
magnet positioned a certain distance away from the reed switch body
to close the reed switch by a magnetic field; and a diversion blade
configured to move in and out of a space between the reed switch
body and the bias magnet, such that the diversion blade positioned
in the space opens the reed switch by diverting the magnetic field
applied by the bias magnet.
2. The reed switch assembly of claim 1, wherein the diversion blade
is annular-shaped.
3. The reed switch assembly of claim 2, wherein the diversion blade
is configured to rotate around an axis.
4. The reed switch assembly of claim 3, wherein the diversion blade
extends only partially along a circumference relative to the axis,
such that the rotation of the diversion blade around the axis opens
and closes the reed switch.
5. The reed switch assembly of claim 1, wherein the diversion blade
is substantially straight and elongated along an axis perpendicular
to the reed switch body.
6. The reed switch assembly of claim 5, wherein the diversion blade
is configured to move along the axis perpendicular to the reed
switch body.
7. The reed switch assembly of claim 6, wherein the diversion blade
has a finite length such that the movement of the diversion blade
along the axis opens and closes the reed switch.
8. The reed switch assembly of claim 1, wherein the bias magnet is
attached to an object that is separate from the reed switch
body.
9. The reed switch assembly of claim 1, wherein the bias magnet is
attached to a bracket that is attached to the reed switch body.
10. The reed switch assembly of claim 1, wherein the diversion
blade is composed of soft magnetic materials having low retentivity
and low coercivity.
11. The reed switch assembly of claim 1, wherein the diversion
blade is attached to a rotational object.
12. The reed switch assembly of claim 1, wherein the diversion
blade is configured to move linearly along an axis perpendicular to
the reed switch body.
13. A reed switch assembly comprising: a reed switch comprising: a
first reed contact; a second reed contact; a reed switch body
defining a substantially straight channel and enclosing the first
reed switch contact and the second reed switch contact; and a bias
magnet positioned a certain distance away from the reed switch body
to close the reed switch by a magnetic field; and a yoke configured
to move and surround the bias magnet, such that the yoke, when
moved into a position to surround the bias magnet, opens the reed
switch by diverting the magnetic field applied by the bias
magnet.
14. The reed switch assembly of claim 13, wherein the yoke is
U-shaped when viewed from a first angle.
15. The reed switch assembly of claim 14, wherein the yoke is
partially annular-shaped, when viewed from a second angle
perpendicular to the first angle.
16. The reed switch assembly of claim 15, wherein the yoke is
configured to rotate around an axis.
17. The reed switch assembly of claim 14, wherein the yoke is
substantially straight and elongated along an axis perpendicular to
the reed switch body, when viewed from a second angle perpendicular
to the first angle.
18. The reed switch assembly of claim 17, wherein the yoke is
configured to move linearly along the axis perpendicular to the
reed switch body.
19. The reed switch assembly of claim 13, wherein the bias magnet
is attached to an object that is separate from the reed switch
body.
20. The reed switch assembly of claim 13, wherein the bias magnet
is attached to a bracket that is attached to the reed switch body.
Description
TECHNICAL FIELD
[0001] The present disclosure relates to a reed switch assembly
that may be used in a variety of contexts. More particularly, the
present disclosure relates to a normally-closed reed switch
assembly that may be customized to provide a desired length of
activation.
BACKGROUND
[0002] A reed switch is an electrical switch operated by an applied
magnetic field. One of the most common types is a Single Pole
Single Throw (SPST) reed switch, which consists of a pair of
contacts on ferromagnetic metal reeds in a hermetically sealed
glass envelope (i.e., reed switch body). The contacts may be
normally open, closing when a magnetic field is applied (i.e., a
normally-open SPST reed switch), or normally closed, opening when a
magnetic field is applied (i.e., a normally-closed SPST reed
switch). The reed switch effectively works like a gate, or a
bridge, in an electric circuit. When the contacts are closed,
electricity can flow around the circuit to operate a device.
[0003] The current state of the art to operate a normally-closed
SPST reed switch is by using two magnets. A fixed magnet is
collocated near the reed switch body (e.g., attached to the reed
switch body) to have the contacts closed, until an opposing
magnetic field is applied by a bias magnet to open the contacts.
Due to the close proximity of the fixed magnet to the contacts, the
size, type, and position of the fixed magnet may be carefully
considered to maintain the contacts stabilized in the closed or
open position. Further, with either the normally-closed SPST reed
switch or the normally-open SPST reed switch of the current state
of the art, the physical distance of activation (i.e., being in an
abnormal position) is limited.
[0004] The background description provided herein is for the
purpose of generally presenting the context of the disclosure.
Unless otherwise indicated herein, the materials described in this
section are not prior art to the claims in this application and are
not admitted to be prior art, or suggestions of the prior art, by
inclusion in this section.
SUMMARY OF THE INVENTION
[0005] One embodiment provides a reed switch assembly comprising: a
reed switch comprising: a first reed contact; a second reed
contact; a reed switch body defining a substantially straight
channel and enclosing the first reed contact and the second reed
contact; and a bias magnet positioned a certain distance away from
the reed switch body to close the reed switch by a magnetic field;
and a diversion blade configured to move in and out of a space
between the reed switch body and the bias magnet, such that the
diversion blade positioned in the space opens the reed switch by
diverting the magnetic field applied by the bias magnet.
[0006] One embodiment provides a reed switch assembly comprising: a
reed switch comprising: a first reed contact; a second reed
contact; a reed switch body defining a substantially straight
channel and enclosing the first reed contact and the second reed
contact; and a bias magnet positioned a certain distance away from
the reed switch body to close the reed switch by a magnetic field;
and a yoke configured to move and surround the bias magnet, such
that the yoke, when moved into a position to surround the bias
magnet, opens the reed switch by diverting the magnetic field
applied by the bias magnet.
[0007] The foregoing and other objects and advantages will appear
from the description to follow. In the description reference is
made to the accompanying drawings, which form a part hereof, and in
which is shown by way of illustration specific embodiments in which
the invention may be practiced. These embodiments will be described
in sufficient detail to enable those skilled in the art to practice
the invention, and it is to be understood that other embodiments
may be utilized and that structural changes may be made without
departing from the scope of the invention. In the accompanying
drawings, like reference characters designate the same or similar
parts throughout the several views.
[0008] The following detailed description is, therefore, not to be
taken in a limiting sense, and the scope of the present invention
is best defined by the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Embodiments of the present disclosure will now be described,
by way of example only, with reference to the accompanying drawings
in which:
[0010] FIG. 1A shows a view along the x-y plane of a
normally-closed SPST reed switch assembly in a "normal" state.
[0011] FIG. 1B shows a view along the x-y plane of a
normally-closed SPST reed switch assembly in an "abnormal"
state.
[0012] FIG. 1C shows a view along the x-y plane of a
normally-closed SPST reed switch assembly in an "overdriven"
state.
[0013] FIG. 2A shows a view along the x-y plane of an exemplary
normally-closed SPST reed switch assembly in a "normal" state,
according to one aspect of the present disclosure.
[0014] FIG. 2B shows the exemplary normally-closed SPST reed switch
assembly of FIG. 2A along the y-z plane, according to one aspect of
the present disclosure.
[0015] FIG. 2C shows a view along the x-y plane of an exemplary
normally-closed SPST reed switch assembly in an "abnormal" state,
according to one aspect of the present disclosure.
[0016] FIG. 2D shows the exemplary normally-closed SPST reed switch
assembly of FIG. 2C along the y-z plane, according to one aspect of
the present disclosure.
[0017] FIG. 3 shows a perspective view of an exemplary
normally-closed SPST reed switch device, according to one aspect of
the present disclosure.
[0018] FIG. 4A shows a perspective view of the exemplary
normally-closed SPST reed switch device of FIG. 3 implemented with
a yoke, according to one aspect of the present disclosure.
[0019] FIG. 4B shows a view along the x-y plane of the exemplary
normally-closed SPST reed switch and the yoke depicted in FIG. 4A,
according to one aspect of the present disclosure.
[0020] FIG. 5A shows a perspective view of the exemplary
normally-closed SPST reed switch device and the yoke depicted in
FIG. 4A, with the yoke being attached to a rotational object,
according to one aspect of the present disclosure.
[0021] FIG. 5B shows another perspective view of the exemplary
normally-closed SPST reed switch device and the yoke depicted in
FIG. 4A, with the yoke being attached to a rotational object,
according to one aspect of the present disclosure.
[0022] FIG. 6A show a perspective view of the exemplary
normally-closed SPST reed switch device of FIG. 3 implemented with
a yoke, according to one aspect of the present disclosure.
[0023] FIG. 6B shows a view along the x-y plane of the exemplary
normally-closed SPST reed switch and the yoke depicted in FIG. 6A,
according to one aspect of the present disclosure.
[0024] FIG. 7A shows a perspective view of the exemplary
normally-closed SPST reed switch of FIG. 3 implemented with a
diversion blade, according to one aspect of the present
disclosure.
[0025] FIG. 7B shows a perspective view of the exemplary
normally-closed SPST reed switch of FIG. 3 implemented with a
diversion blade that is configured differently from the diversion
blade of FIG. 7A, according to one aspect of the present
disclosure.
DETAILED DESCRIPTION
[0026] The following embodiments describe a reed switch assembly
that may be used in a variety of contexts. More particularly, the
following embodiments relate to a normally-closed SPST reed switch
assembly that may be customized to provide a desired length of
activation.
[0027] The SPST reed switch is inherently normally open. Second
party vendors add bias magnets within the reed switch packaging to
transform the normally-open SPST reed switch to a normally-closed
SPST reed switch. FIG. 1A shows a view along the x-y plane of a
normally-closed SPST reed switch assembly in a "normal" state. In
general, a normally-closed SPST reed switch assembly 100 may
include a first reed contact 12, a second reed contact 14, a reed
switch body 16, a bias magnet 10, and a switching magnet 18 (not
shown in FIG. 1A, but shown in FIGS. 1B-1C). In the "normal" or
"closed" state, the first reed contact 12 and the second reed
contact 14 may be magnetically polarized by the magnetic field
generated by the bias magnet 10, which may be attached to the outer
surface of the reed switch body 16. Due to the magnetic
polarization, contacts 12 and 14 become magnetically attracted to
each other, closing the switch.
[0028] FIG. 1B shows a view along the x-y plane of a
normally-closed SPST reed switch assembly in an "abnormal" state.
In the "abnormal" or "open" state, the first reed contact 12 and
the second reed contact 14 may be depolarized by the magnetic field
generated by a switching magnet 18, which counters the magnetic
field strength and polarity generated by the bias magnet 10 to open
the switch. When the switching magnet 18 is moved close to the reed
switch body 16, contacts 12 and 14 may repel one another due to the
opposing magnetic field generated by the switching magnet 18,
opening the switch.
[0029] The direction and the strength of the magnetic field (i.e.,
magnetic flux) generated by the switching magnet 18 may need to be
precisely controlled to switch the state of the reed switch from
"closed" to "open," and to keep it open in a stable manner. In
other words, the magnetic polarization of the contacts 12 and 14,
which is induced by the bias magnet 10, needs to be correctly
countered/canceled by the switching magnet 18, by generating an
opposing magnetic field of specific direction and strength. For
instance, if the field is too weak, the switch will not open. On
the other hand, if the field is too strong, the switch will be
overdriven and become closed, with the contacts 12 and 14 polarized
in the opposite direction (compared to FIG. 1A). FIG. 1C depicts a
view along the x-y plane of a normally-closed SPST reed switch
assembly in such an "overdriven" state. Therefore, the magnetic
field generated by the switching magnet 18 needs to remain in
direct opposition to that of the bias magnet 10, and stay within a
set value of opposition strength.
[0030] The magnetic field strength of the bias magnet 10 may need
to be substantially smaller compared to that of the switching
magnet 18, due to the close proximity of the bias magnet 10 to the
reed contacts 12 and 14. Due to this limitation, the magnetic
material of choice for the bias magnet 10 may be ceramic (e.g.,
Strontium Ferrite). Ceramic magnets may not be nearly as stable
against varying temperature (e.g., high temperature) as magnets
composed of other temperature-stable materials. For instance,
ceramic magnets may have magnetic strength temperature coefficients
ranging approximately from -0.2 to -0.3%/.degree. C. The magnetic
strength temperature coefficients represent the percent change in
the intrinsic coercive field strength per degree Celsius. Because
of the poor temperature linearity, the operational temperature
range for the reed switch may be limited in applications requiring
higher degrees of accuracy. The more temperature-stable magnets may
be much higher powered (i.e., higher magnetic field strength) and
may become fragile if used as the bias magnet 10 in the
configuration shown in FIGS. 1A-1B, as the size of the magnet may
need to be very small to achieve a desired strength (i.e., not to
overdrive the proximately-positioned reed contacts 12 and 14).
[0031] With conventional normally-open or normally-closed SPST reed
switches, the physical distance of activation (i.e., being in an
"abnormal" state) may also be limited. For example, if a reed
switch is set to pass over magnetic fields that change directions
(e.g., pass over a line of magnets), the switch may flutter between
"normal" and "abnormal" states. Maintaining a constant flux
direction over an extended distance may not be possible with the
conventional normally-closed SPST reed switch, and an elaborate
circuit/assembly with back path yokes may be necessary for the
normally-open SPST switch.
[0032] Therefore, there is a need for a reed switch assembly that
is compatible with magnets of varying characteristics, such as,
e.g., magnetic strengths and temperature coefficients. Further, it
would be desirable to have a customizable reed switch assembly, to
facilitate customizing the distance and/or duration of the reed
switch activation.
[0033] One disclosed embodiment is directed to a normally-closed
SPST reed switch assembly comprising a reed switch and a diversion
blade. In particular, the reed switch may comprise a bias magnet
positioned a certain distance away from a reed switch body
enclosing reed contacts. The diversion blade may be configured to
be mobile, such that the diversion blade may be positioned between
the bias magnet and the reed switch body for a desired distance
and/or duration. Thus, the disclosed embodiment may allow use of a
more powerful, temperature-stable magnet compared to that of, for
example, the reed switch assembly 100 depicted in FIGS. 1A-1C, and
may allow for a customizable activation distance/duration.
[0034] The subject matter herein will now be described more fully
hereinafter with reference to the accompanying drawings, which form
a part hereof, and which show, by way of illustration, specific
exemplary embodiments. An embodiment or implementation described
herein as "exemplary" is not to be construed as preferred or
advantageous, for example, over other embodiments or
implementations; rather, it is intended to reflect or indicate that
the embodiment(s) is/are "example" embodiment(s). Subject matter
may be embodied in a variety of different forms and, therefore,
covered or claimed subject matter is intended to be construed as
not being limited to any exemplary embodiments set forth herein;
exemplary embodiments are provided merely to be illustrative.
Likewise, a reasonably broad scope for claimed or covered subject
matter is intended. Among other things, for example, subject matter
may be embodied as methods, devices, components, or systems. The
following detailed description is, therefore, not intended to be
taken in a limiting sense.
[0035] Throughout the specification and claims, terms may have
nuanced meanings suggested or implied in context beyond an
explicitly stated meaning. Likewise, the phrase "in one embodiment"
as used herein does not necessarily refer to the same embodiment
and the phrase "in another embodiment" as used herein does not
necessarily refer to a different embodiment. It is intended, for
example, that claimed subject matter include combinations of
exemplary embodiments in whole or in part.
[0036] Referring now to the drawings illustrative of the
contemplated embodiments, FIG. 2A shows a view along the x-y plane
of an exemplary normally-closed SPST reed switch assembly in a
"normal" state, according to one aspect of the present disclosure.
FIG. 2B shows the exemplary normally-closed SPST reed switch
assembly of FIG. 2A along the y-z plane, according to one aspect of
the present disclosure. In the discussion below, reference will be
made to both FIG. 2A and FIG. 2B. In general, the normally-closed
SPST reed switch assembly 200 may comprise a first reed contact 12,
a second reed contact 14, a reed switch body 16, a bias magnet 20,
and a diversion blade 22. Notably, the normally-closed SPST reed
switch assembly 200 may use a single magnet (e.g., only the bias
magnet 20) and a diversion blade 22, to close and open the
switch.
[0037] In the "normal" or "closed" state, the first reed contact 12
and the second reed contact 14 may be magnetically polarized by a
magnetic field generated by the bias magnet 20. Due to the magnetic
polarization, contacts 12 and 14 become magnetically attracted to
each other, closing the switch. Notably, the bias magnet 20 may not
be attached to the reed switch body 16, and may be positioned a
certain distance away from the reed switch body 16. Positioning the
bias magnet 20 "away" from the reed switch body 16 and keeping a
certain amount of distance therebetween may allow the use of a more
temperature-stable, higher-powered magnet as the bias magnet 20,
because the risk of overdriving the reed contacts 12 and 14 may be
reduced or minimized under this configuration. For example, more
powerful, standard size temperature-stable magnets such as, e.g.,
Sumarium Cobalt, which has a magnetic strength temperature
coefficient of approximately -0.04%/.degree. C., may be used as the
bias magnet 20, due to the greater physical separation from the
reed contacts 12 and 14. Another material of choice is Neodymium.
Each of Sumarium Cobalt and Neodymium may have sufficient magnetic
strength to be used at separation distances (i.e., distance between
the bias magnet 20 and the reed contacts 12 and 14) up to and
likely greater than 0.25 inches. However, the material of the bias
magnet 20 may not be limited to Sumarium Cobalt and Neodymium.
Weaker magnets formed of temperature-stable Alnico or less
temperature-stable Ceramic (e.g., Hexagonal Ferrite) may also be
used in applications where closer separation is acceptable.
Nonetheless, the stronger and more temperature-stable Sumarium
Cobalt or Neodymium that allows for i) a greater physical
separation from the reed contacts 12 and 14 (such that the blade 22
may not mechanically interfere with the reed switch body 16 over
the travel distance) and ii) a wider operational temperature range
may be preferred. The perpendicular distance (i.e., the shortest
distance) between the bias magnet 20 and the reed switch body 16
may be large enough to pass a diversion blade 22 through the space
between the bias magnet 20 and the reed switch body 16. In other
words, the perpendicular distance may be larger than the thickness
of the diversion blade 22.
[0038] It should be noted that the diversion blade 22 in FIG. 2A is
illustrated as a dotted box, because the diversion blade 22 has not
been positioned between the bias magnet 20 and the reed switch body
16 yet. This is shown more clearly in FIG. 2B. As shown in FIG. 2B,
when the reed switch is in the "normal" or "closed" state, the
diversion blade 22 may not be positioned between the bias magnet 20
and the reed switch body 16, either partially or entirely.
Therefore, the magnetic field generated by the bias magnet 20 is
not interfered by any object and may polarize the reed contacts 12
and 14 to attract each other. However, as indicated by the arrow
next to the diversion blade 22 in FIG. 2B, the diversion blade 22
may be moved along the z-axis and may be positioned between the
bias magnet 20 and the reed switch body 16, as discussed below in
greater detail.
[0039] FIG. 2C shows a view along the x-y plane of an exemplary
normally-closed SPST reed switch assembly in an "abnormal" state,
according to one aspect of the present disclosure. FIG. 2D shows
the exemplary normally-closed SPST reed switch assembly of FIG. 2C
along the y-z plane, according to one aspect of the present
disclosure. In the following discussion, reference will be made to
both FIG. 2C and FIG. 2D.
[0040] In the "abnormal" or "open" state, the first reed contact 12
and the second reed contact 14 may be opened by positioning the
diversion blade 22 in between the bias magnet 20 and the reed
switch body 16. The diversion blade 22 may be made of soft magnetic
material(s), which have low retentivity and low coercivity, such
as, e.g., Iron-Silicon alloys, Nickel-Iron alloys, Iron, etc. These
soft magnetic materials may also have high initial permeability,
low hysteresis loss, and large magnetic induction. Therefore,
placement of the diversion blade 22 between the bias magnet 20 and
the reed switch body 16 may suspend polarization of the reed
contacts 12 and 14, by diverting the magnetic field generated by
the bias magnet 20 away from the reed contacts 12 and 14. Because
the reed contacts 12 and 14 are no longer polarized, they may
revert to the "open" state as shown in FIG. 2C.
[0041] As shown in FIG. 2D, the diversion blade 22 may only need to
be partially positioned between the bias magnet 20 and the reed
switch body 16 along the z-axis, and may still be able to divert a
sufficient portion of the magnetic field to depolarize and open the
reed contacts 12 and 14. More particularly, the diversion blade 22
may be moved at least to the centerline position along the z-axis,
as indicated by the dotted vertical line in FIG. 2D, to open the
switch. As alluded to above, the diversion blade 22 may continue to
move along the z-axis (e.g., move to left in FIG. 2D) at a desired
rate, such that the switch remains open for a desire duration until
the diversion blade 22 moves past the centerline. Therefore, the
length/duration of the actuation may be decided based on the length
of the diversion blade 22 as well as the rate of the movement, both
of which may be customizable based on specific needs and
applications. Diversion blade 22 may also be moved in the other
direction, e.g., from left to right in FIG. 2D, and may achieve the
same effects discussed above.
[0042] FIG. 3 shows a perspective view of an exemplary
normally-closed SPST reed switch device, according to one aspect of
the present disclosure. Notably, the reed switch device 300 may
employ the concepts and configurations of the reed switch assembly
200 discussed above in reference to FIGS. 2A-2C. In general, the
reed switch device 300 may comprise a reed switch body 16 enclosing
a first reed contact 12 and a second reed contact 14, and a bracket
30 with a bias magnet 20 embedded therein.
[0043] As shown in FIG. 3, the reed contacts 12 and 14 may be
encased in a reed switch body 16, which may be tubular,
hermetically-sealed glass capsule filled with an unreactive gas
(e.g., Nitrogen). In some embodiments, the reed switch body 16 may
further comprise an outer casing made of plastic, to enclose and
protect the glass capsule from damage. The reed contacts 12 and 14
may be made of ferromagnetic material(s) and may be coated with a
hard wearing metal such as, e.g., Rhodium or Ruthenium. In order to
position the bias magnet 20 a certain distance away from the reed
contacts 12 and 14, an object may be used to hold the bias magnet
20 at a desired location relative to the reed switch body 16. An
optimal location may be chosen such that the bias magnet 20 held at
the selected location may close the contacts 12 and 14 (to achieve
a "closed" state") in the absence of any obstructing object (e.g.,
diversion blade 22), and such that a diversion blade 22 may move in
and out of the space between the bias magnet 20 and the reed switch
body 16. The object used to hold the bias magnet 20 may be attached
to the reed switch body 16. For example, as shown in FIG. 3, a
bracket 30 attached to the reed switch body 16 may be used to hold
the bias magnet 20 at the optimal location. In other embodiments,
the object used to hold the bias magnet 20 may not be attached to
the reed switch body 16, and may be attached to a structure
independent and/or separate from the reed switch body 16.
Regardless of the type of object used to hold the bias magnet 20,
the position of the bias magnet 20 relative to the reed contacts 12
and 14 needs to be maintained at the optimal location, such that
the reed switch may remain closed in a stable manner during the
"closed" state (i.e., without fluttering between "closed" and
"open" states).
[0044] FIG. 4A shows a perspective view of the exemplary
normally-closed SPST reed switch device of FIG. 3 implemented with
a yoke, according to one aspect of the present disclosure. FIG. 4B
shows a view along the x-y plane of the exemplary normally-closed
SPST reed switch and the yoke depicted in FIG. 4A. Notably, yoke 40
may be employed to achieve the same, or substantially similar
effect as the diversion blade 22 discussed above in reference to
FIGS. 2A-2D. Reference will be made to both FIG. 4A and FIG. 4B in
the discussion below.
[0045] As shown in FIG. 4B, yoke 40 may be a U-shaped soft magnetic
object, with the opposing plates (i.e., the top and bottom plates)
and the interconnecting blade (i.e., the plate that connects the
top and bottom plates) configured to surround the bias magnet 20
embedded in the bracket 30. In addition to diverting the magnetic
flux away from the reed switch body 16 via the bottom plate, the
yoke 40 may confine largely the magnetic flux generated by the bias
magnet 20 to the space enclosed within the U-shaped structure. As a
result, the yoke 40 may provide an additional benefit of preventing
stray magnetic fields from interfering with other magnetically
sensitive devices nearby. When the yoke 40 is moved into position
as shown in FIGS. 4A-4B (i.e., positioned such that the plates at
least partially surround the bias magnet 40, e.g., at least up to
the centerline discussed above with reference to FIG. 2D, in order
to divert a sufficient amount of magnetic flux from the bias magnet
20 and open the reed switch), the contacts 12 and 14 may become
depolarized and revert to the "open" state. It should be noted
that, although a noticeable space is not visible between the first
reed contact 12 and the second reed contact 14 in FIGS. 4A-4B, the
contacts 12 and 14 are actually separated, leaving a space
therebetween. In reality, the space between the contacts 12 and 14
may be very small (e.g., merely a few microns) and may not be
visible to the naked eye.
[0046] Further, as shown in FIG. 4A, yoke 40 may be curved or
partially annular-shaped (i.e., arc-shaped). For example, yoke 40
may be partially annular-shaped and attached to an object that
rotates around an axis. Such a rotational object may be cylindrical
or cone-shaped, and the yoke 40 may be attached to the outer wall
of the rotational device, as shown in FIGS. 5A-5B. FIG. 5A shows a
perspective view of the exemplary normally-closed SPST reed switch
device and the yoke depicted in FIG. 4A, with the yoke attached to
a rotational object, according to one aspect of the present
disclosure. In particular, the reed switch in FIG. 5A is in a
"normal" or "closed" state, because the yoke 40 is not "in
position" yet. FIG. 5B similarly shows a perspective view of the
exemplary normally-closed SPST reed switch device and the yoke
attached to a rotational object, but with the reed switch in an
"abnormal" or "open" state (i.e., when the yoke 40 is "in
position"). As shown in FIGS. 5A-5B, rotating the yoke 40 around an
axis may transition the state of the reed switch between "closed"
and "open" states. The length/duration of activation may depend on
the length (i.e., circumferential length) of the yoke 40 and the
rate of rotation around the axis, both of which may be customizable
based on specific needs and/or applications. In some embodiments,
the yoke 40 may not be attached to such an object depicted in FIGS.
5A-5B, and may rotate around an axis by using any suitable means.
In some embodiments, the yoke 40 may be curved in a direction
opposite to that of the curvature depicted in FIGS. 4A-4B and FIGS.
5A-5B, such that the axis by which the yoke 40 rotates may be on
the other side of the reed switch device 300. For instance, FIGS.
7A-7B show a partially annular-shaped diversion blade 22 curved in
opposite directions. Likewise, the curvature direction of the yoke
40 may be varied based on the application context.
[0047] FIG. 6A show a perspective view of an exemplary
normally-closed SPST reed switch device of FIG. 3 implemented with
a yoke, according to another aspect of the present disclosure. FIG.
6B shows a view along the x-y plane of the exemplary
normally-closed SPST reed switch and the yoke depicted in FIG. 6A.
Notably, yoke 60 may be employed to achieve the same, or
substantially similar effect as the diversion blade 22 discussed
above in reference to FIGS. 2A-2D, and as the yoke 40 discussed
above in reference to FIGS. 4A-4B. Further, while yoke 60 may
operate in a similar manner as the yoke 40 depicted in FIGS. 4A-4B,
the physical construction of the yoke 60 may be distinct from yoke
40, in that yoke 60 may be straight or substantially straight and
may move linearly along an axis (as opposed to rotating around an
axis). Reference will be made to both FIG. 6A and FIG. 6B in the
discussion below.
[0048] As shown in FIG. 6B, yoke 60 may be a U-shaped soft magnetic
object, with the opposing plates (i.e., the top and bottom plates)
and the interconnecting blade (i.e., the plate that connects the
top and bottom plates) configured to surround the bias magnet 20
embedded in the bracket 30. In addition to diverting the magnetic
flux away from the reed switch body 16 via the bottom plate, the
yoke 60 may confine largely the magnetic flux generated by the bias
magnet 20 to the space enclosed within the U-shaped structure.
Therefore, when the yoke 60 is moved into position (i.e.,
positioned such that the plates at least partially surround the
bias magnet 40, e.g., at least up to the centerline discussed above
with reference to FIG. 2D, in order to divert a sufficient amount
of the magnetic flux from the bias magnet 20 and open the reed
switch), the contacts 12 and 14 may become depolarized and revert
to the "open" state. Further, as shown in FIG. 6A, yoke 60 may be
straight or substantially straight, and may extend along an axis
(e.g., z-axis). Yoke 60 may move linearly along the z-axis (in the
positive z direction), as indicated by the arrow in FIG. 6A, to
transition the state of the reed switch between "closed" and "open"
states. Yoke 60 may also move in the opposite direction (in the
negative z direction). The length/duration of activation may depend
on the length of the yoke 60 and the rate of movement along the
z-axis, both of which may be customizable based on specific needs
and/or applications. Yoke 60 illustrated in FIGS. 6A-6B may operate
under the same, or substantially similar principles as those
explained with respect to FIGS. 4A-4B, except that yoke 60 may move
in straight line along an axis, rather than rotating around an
axis.
[0049] It is further noted that, in FIGS. 4A-4B, 5A-5B, and 6A-6B,
the U-shaped object (e.g., yokes 40 and 60) is depicted as an
exemplary device to divert the magnetic flux of the bias magnet 20.
As explained above, a yoke may comprise three plates together
forming a U-shaped configuration, to largely confine the magnetic
flux within its enclosed space. However, an object shaped like the
diversion blade 22 depicted in reference to FIGS. 2A-2D may also
achieve the same effect of transitioning the state of the reed
switch from "closed" to "open" (and vice versa). Diversion blade 22
may be a straight, planar, soft magnetic object that is configured
to move in and out of the space between the bias magnet 20 and the
reed switch body 16, to divert the magnetic flux from the bias
magnet 20 away from the reed contacts 12 and 14. Like the yokes 40
and 60, the diversion blade 22 may be partially annular-shaped and
may rotate around an axis, as shown in FIGS. 7A-7B, or may be
straight or substantially straight and may move in straight line
along an axis. In short, the operating principles explained with
reference to FIGS. 4A-4B, 5A-5B, and 6A-6B (i.e., with respect to
yokes 40 and 60) may equally apply to the diversion blade 22.
[0050] The particular embodiments disclosed above are illustrative
only and should not be taken as limitations, as the embodiments may
be modified and practiced in different but equivalent manners
apparent to those skilled in the art having the benefit of the
teachings herein. Accordingly, the foregoing description is not
intended to limit the disclosure to the particular form set forth,
but on the contrary, is intended to cover such alternatives,
modifications, and equivalents as may be included within the spirit
and scope of the inventions so that those skilled in the art should
understand that they can make various changes, substitutions, and
alterations without departing from the spirit and scope of the
inventions in their broadest form.
[0051] Although various embodiments of the present disclosure have
been illustrated and described in detail, it will be readily
apparent to those skilled in the art that various modifications may
be made without departing from the present disclosure or from the
scope of the appended claims.
* * * * *